For example if I am a Wireless Internet Service Provider and I have own IP for my subscribers. If a subscriber connect first using the wireless dongle (Ex. Huawei or ZTE) and my server open the port and connect it using our standard IP address. The subscriber now opens a Tunneling software like Ultrasurf which changes the IP address. Can my server detect the change of IP address? Can the server forcibly close the port to disconnect the network because of new IP address?